Structures such as buildings, automobiles, marine vehicles and aircrafts are typically coated for preventative and aesthetic purposes and experience degradation based on environmental conditions. The environmental conditions can include rain, high winds, humidity, heat and salt spray, and other conditions which can potentially cause external and internal damages to the substrates of the structures. Some problems detected include corrosion, mold, cracks, scratches, delamination, and material fatigue, for example.
Conventional methods of detecting these abnormalities include visual inspection, x-ray, eddy current and capacitance point measurements or heating the substrate to generate infrared light for detection of any abnormalities of the substrate.